1. Field of the Invention
The present in vention relates to roll films and to photographic cameras for use therewith. More particularly, the invention relates to improvements in roll films and cooperating camera elements for automatically coupling the leading end of the film to a film take-up spool in a camera.
2. Description Relative to the Prior Art
When loading conventional 35 mm cameras with roll film, the operator must (1) insert the film cassette into a film supply chamber, (2) pull the film leader out of the cassette and position it along film guide rails that cooperate with other camera structure to define a film passageway extending between the supply chamber and a take-up chamber. (3) attach the end of the film leader to a film take-up spool rotatably mounted in the take-up chamber, (4) turn the film advance lever to wind the film around the take-up spool, making sure that the sprocket holes in the film are engaged in the teeth of the film transport sprocket, (5) close the camera back cover until it snaps shut, and (6) gently turn the film rewind crank to take up any film slack. If the film is not properly loaded, the operator must open the back cover, which may entail the loss of one or more exposure frames, and repeat the film loading procedure from the start. Many amateur photographers find this manual film loading procedure to be tedious, complicated and of uncertain result.
35 mm cameras provided with automatic film loading devices are known in the art. However, in the presently known devices, all the active components of the loading apparatus are provided by camera structure which acts upon a roll film fed into the film take-up chamber. For example, U.S. Pat. No. 3,377,936 to Takeshi Goshima et al discloses film-loading apparatus for 35 mm cameras in which the leading end of a standard 35 mm film strip, fed by means of a sprocket or the like, is automatically connected to a take-up spool by friction imparted by spring biased friction members provided on the spool.
It is also known to provide the leading end of a film or web with a shaped aperture which cooperates with machine structure during an automatic loading procedure. See, for example commonly assigned U.S. Pat. No. 3,724,776 to Edward S. McKee and U.S. Pat. No. 3,619,050 to Thaddeus Swanke respectively disclosing motion picture projector apparatus and electrophotographic copier apparatus. Here too, however, the apertured film or web is passive during loading and is merely acted upon by the apparatus in which it is used.
As a result of the purely passive role of the film or web in the prior art automatic loading techniques, the cooperating machine structure must be mechanically complex in order to ensure reliable connection of the film.